Flexible packages, and particularly resealable and reclosable packages, are frequently used for packaging consumable products. Products that are not completely used when the package is initially opened rely upon a zipper closure to reclose the package and keep the remaining contents fresh. Examples of consumable products that are often provided in reclosable packages with a zipper closure include potting soil, fertilizer, pet food, dog biscuits, vegetables, cereal and many different types of food, such as cheese, edible by humans.
Often, the opening and closing of the zipper closure is facilitated by a slider device that is mounted on the zipper closure. The slider device is constructed to pry apart the interlocking zipper closure members when the slider device is moved in a first direction and to engage the interlocking zipper closure members when the slider device is moved in a second, opposite direction. For some applications, a tamper-evident structure is desired to indicate whether access has been gained to the zipper closure.
As discussed above, a typical reclosable package includes a pair of opposing side panels joined to each other along a pair of side seals and a bottom wall that extends between the side panels to define a three-sided, open package interior. The reclosable zipper closure extends along an open mouth of the package opposite the bottom wall. The zipper closure includes a first profile member and a second profile member that are adapted to resealably interlock with each other.
If reclosable packages are to be prepackaged with a product and sold in the stores, the packages are typically prepared on a horizontal or vertical form, fill and seal machine. In this type of machine, the reclosable package is first formed into the shape of a pouch having a fill opening at either the top or the bottom. If the fill opening is disposed at the bottom of the package, the zipper closure is attached between the side panels and the top of the package is sealed prior to filling the product into the package.
If the package is designed to be filled from the top, the bottom is initially sealed prior to filling of the product. Next, the package is filled with product through a fill opening near the mouth of the package.
One method of top filling a package with product is to fill the product through the zipper closure when the first and second profile elements of the zipper closure are in an unmated condition. This type of filling is typically referred to as the “fill through the zipper” method. Once the product has been placed into the package interior, the zipper closure is either mated or left unmated and the top edges of the package are sealed. This type of filling arrangement includes several inherent disadvantages, such as the requirement that the zipper closure must be mated after filling.
Alternatively, U.S. Pat. No. 6,071,011 teaches a method of attaching the zipper closure to only one of the side panels prior to the product being inserted into the package interior. The package is then filled with product through a fill opening between the zipper closure and the opposite side panel to which the zipper closure is not yet attached. After the package interior has been filled with product, the zipper closure is sealed to the opposite side panel and the top of the package sealed. The method taught by the ′011 patent provides the advantage of allowing the zipper closure to remain in the mated condition during package filling. Improvements to this type of method of filling are desired.